All-Sky Catalog of Faint EUV Sources

The joint selection criterion within a 1.5 arcminute positional tolerance permitted the use of a low count rate threshold in each survey. This low threshold was roughly 60% of the threshold used in the previous EUVE all-sky surveys, and 166 of the objects listed in this table were new EUV sources, appearing neither in the Second EUVE Source Catalog nor in the ROSAT Wide Field Camera Second Catalog.

Preliminary identifications are offered for 105 of the 166 sources not previously reported in any EUV catalog: by far the most numerous (81) of the identifications are late-type (F-M) stars, while 18 are other stellar types, only 5 are white dwarfs, and none are extragalactic. The paucity of WDs and extragalactic objects may be explained by a strong horizon effect wherein interstellar absorption strongly limits the effective new-source search volume, and, thereby, selectively favors low-luminosity nearby sources over more luminous but distant objects.